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The real cost of self-hosting Sentry

3 min read

Self-hosted Sentry is genuinely free software, and for some teams it's the right call. But 'free' is a license price, not a total cost. Having run a production self-hosted Sentry ourselves, here is what the bill actually looks like — in hardware, in upgrades, and in the 3 a.m. pages you inherit.

What you're actually operating

Sentry stopped being 'a Django app with Postgres' many years ago. A current self-hosted install runs on the order of fifty containers: the web app and workers, Kafka and Zookeeper, ClickHouse for event analytics, Redis, Postgres, Snuba query services, Relay for ingestion, symbolicator, vroom for profiling, and a mesh of consumers wiring them together.

The official minimum requirements are 4 CPU cores and 16 GB RAM — and that's the floor for a small install, before real traffic, before retention, before profiling.

The honest TCO line items

Line itemTypical costNotes
Server(s)$80–$400/moA 16 GB box is the entry point; teams with real volume run several.
Storage growthgrows monthlyClickHouse + Kafka retention needs active pruning or the disk fills.
Upgrades2–6 hrs/monthSentry ships fast; self-hosted upgrades occasionally involve breaking migration steps.
Monitoring the monitoryour pagerWhen Kafka lags or a consumer dies, error reporting silently stops — and nothing tells you.
Engineer timethe big oneA day a month of a senior engineer often costs more than every SaaS plan combined.

The failure mode nobody prices in

The worst property of self-hosted monitoring is that it fails silently in the same incidents it exists to catch. A full disk, a stuck Kafka consumer or an OOM-killed worker doesn't page you — it just stops ingesting. You find out days later, when someone asks why the dashboard has been quiet. You end up building a second monitoring system to watch the first one.

When self-hosting is the right call

  • Hard data-residency requirements — the data legally cannot leave your infrastructure.
  • Existing platform team — you already run Kafka and ClickHouse for other workloads, so the marginal operational cost is genuinely low.
  • Massive volume with cheap hardware — at extreme event volumes, owned hardware can beat any per-event SaaS price.

The middle path: keep the SDKs, drop the ops

The trap in this decision is thinking it's self-hosted Sentry or SaaS Sentry. Because the Sentry SDK protocol is open, a third option exists: keep every SDK exactly as it is and point the DSN at a hosted, Sentry-compatible backend. That's what jentry is — hosted error tracking, APM, replays and release health that speaks the Sentry protocol, at a flat price, with no Kafka to babysit.

# the entire migration
- dsn: "https://key@your-sentry-box.internal/1"
+ dsn: "https://key@jentry.app/1"

We did exactly this migration ourselves — jentry's own production apps report to jentry, and the self-hosted Sentry install they came from is powered off. The SDKs never changed.

Frequently asked questions

Is self-hosted Sentry really free?

The software is free (FSL-licensed, source available). The cost is the infrastructure it runs on and the engineering time to keep it healthy and upgraded — commonly hundreds of dollars a month in practice.

How much hardware does self-hosted Sentry need?

The documented minimum is 4 CPU cores and 16 GB RAM for the ~50-container stack. Production installs with real traffic and retention typically need more, plus disk that grows continuously.

What breaks most often?

In our experience: disks filling from ClickHouse/Kafka retention, consumers lagging after restarts, and upgrades that require manual migration steps. Each failure stops ingestion silently.

Can I move off self-hosted Sentry without touching my apps?

Yes. Sentry SDKs send to whatever DSN you configure. Point the DSN at a compatible backend like jentry and errors, transactions and releases keep flowing — no code changes.

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Self-Hosted Sentry: The Real Cost of Running It Yourself | jentry